Knee walker



FIG. 1 is a front perspective view of a knee walker, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is an enlarged view of a portion indicated with numeric 9 in FIG. 1 ; and,

FIG. 10 is an enlarged view of a portion indicated with numeric 10 in FIG. 1 .

The dash dot dash lines in FIGS. 1, 9 and 10 are for the purpose of depicting the cut line of the enlarged view and form no part of the claim. 

CLAIM The ornamental design for a knee walker, as shown and described. 